# -*- coding: utf-8 -*-
# -----------------------------------------------------------------------------
# Copyright © Spyder Project Contributors
#
# Licensed under the terms of the MIT License
# (see spyder/__init__.py for details)
# ----------------------------------------------------------------------------

"""
Collections (i.e. dictionary, list, set and tuple) editor widget and dialog.
"""

#TODO: Multiple selection: open as many editors (array/dict/...) as necessary,
#      at the same time

# pylint: disable=C0103
# pylint: disable=R0903
# pylint: disable=R0911
# pylint: disable=R0201

# Standard library imports
from __future__ import print_function
import datetime
import re
import sys
import warnings

# Third party imports
from qtpy.compat import getsavefilename, to_qvariant
from qtpy.QtCore import (
    QAbstractTableModel, QItemSelectionModel, QModelIndex, Qt, Signal, Slot)
from qtpy.QtGui import QColor, QKeySequence
from qtpy.QtWidgets import (
    QApplication, QHBoxLayout, QHeaderView, QInputDialog, QLineEdit, QMenu,
    QMessageBox, QPushButton, QTableView, QVBoxLayout, QWidget)
from spyder_kernels.utils.lazymodules import (
    FakeObject, numpy as np, pandas as pd, PIL)
from spyder_kernels.utils.misc import fix_reference_name
from spyder_kernels.utils.nsview import (
    display_to_value, get_human_readable_type, get_numeric_numpy_types,
    get_numpy_type_string, get_object_attrs, get_size, get_type_string,
    sort_against, try_to_eval, unsorted_unique, value_to_display
)

# Local imports
from spyder.api.config.mixins import SpyderConfigurationAccessor
from spyder.api.widgets.toolbars import SpyderToolbar
from spyder.config.base import _, running_under_pytest
from spyder.config.fonts import DEFAULT_SMALL_DELTA
from spyder.config.gui import get_font
from spyder.py3compat import (io, is_binary_string, PY3, to_text_string,
                              is_type_text_string, NUMERIC_TYPES)
from spyder.utils.icon_manager import ima
from spyder.utils.misc import getcwd_or_home
from spyder.utils.qthelpers import (
    add_actions, create_action, MENU_SEPARATOR, mimedata2url)
from spyder.utils.stringmatching import get_search_scores, get_search_regex
from spyder.plugins.variableexplorer.widgets.collectionsdelegate import (
    CollectionsDelegate)
from spyder.plugins.variableexplorer.widgets.importwizard import ImportWizard
from spyder.widgets.helperwidgets import CustomSortFilterProxy
from spyder.plugins.variableexplorer.widgets.basedialog import BaseDialog
from spyder.utils.palette import SpyderPalette
from spyder.utils.stylesheet import PANES_TOOLBAR_STYLESHEET


# Maximum length of a serialized variable to be set in the kernel
MAX_SERIALIZED_LENGHT = 1e6

LARGE_NROWS = 100
ROWS_TO_LOAD = 50


def natsort(s):
    """
    Natural sorting, e.g. test3 comes before test100.
    Taken from https://stackoverflow.com/a/16090640/3110740
    """
    if not isinstance(s, (str, bytes)):
        return s
    x = [int(t) if t.isdigit() else t.lower() for t in re.split('([0-9]+)', s)]
    return x


class ProxyObject(object):
    """Dictionary proxy to an unknown object."""

    def __init__(self, obj):
        """Constructor."""
        self.__obj__ = obj

    def __len__(self):
        """Get len according to detected attributes."""
        return len(get_object_attrs(self.__obj__))

    def __getitem__(self, key):
        """Get the attribute corresponding to the given key."""
        # Catch NotImplementedError to fix spyder-ide/spyder#6284 in pandas
        # MultiIndex due to NA checking not being supported on a multiindex.
        # Catch AttributeError to fix spyder-ide/spyder#5642 in certain special
        # classes like xml when this method is called on certain attributes.
        # Catch TypeError to prevent fatal Python crash to desktop after
        # modifying certain pandas objects. Fix spyder-ide/spyder#6727.
        # Catch ValueError to allow viewing and editing of pandas offsets.
        # Fix spyder-ide/spyder#6728-
        try:
            attribute_toreturn = getattr(self.__obj__, key)
        except (NotImplementedError, AttributeError, TypeError, ValueError):
            attribute_toreturn = None
        return attribute_toreturn

    def __setitem__(self, key, value):
        """Set attribute corresponding to key with value."""
        # Catch AttributeError to gracefully handle inability to set an
        # attribute due to it not being writeable or set-table.
        # Fix spyder-ide/spyder#6728.
        # Also, catch NotImplementedError for safety.
        try:
            setattr(self.__obj__, key, value)
        except (TypeError, AttributeError, NotImplementedError):
            pass
        except Exception as e:
            if "cannot set values for" not in str(e):
                raise


class ReadOnlyCollectionsModel(QAbstractTableModel):
    """CollectionsEditor Read-Only Table Model"""

    sig_setting_data = Signal()

    def __init__(self, parent, data, title="", names=False,
                 minmax=False, remote=False):
        QAbstractTableModel.__init__(self, parent)
        if data is None:
            data = {}
        self._parent = parent
        self.scores = []
        self.names = names
        self.minmax = minmax
        self.remote = remote
        self.header0 = None
        self._data = None
        self.total_rows = None
        self.showndata = None
        self.keys = None
        self.title = to_text_string(title) # in case title is not a string
        if self.title:
            self.title = self.title + ' - '
        self.sizes = []
        self.types = []
        self.set_data(data)

    def get_data(self):
        """Return model data"""
        return self._data

    def set_data(self, data, coll_filter=None):
        """Set model data"""
        self._data = data

        if (coll_filter is not None and not self.remote and
                isinstance(data, (tuple, list, dict, set))):
            data = coll_filter(data)
        self.showndata = data

        self.header0 = _("Index")
        if self.names:
            self.header0 = _("Name")
        if isinstance(data, tuple):
            self.keys = list(range(len(data)))
            self.title += _("Tuple")
        elif isinstance(data, list):
            self.keys = list(range(len(data)))
            self.title += _("List")
        elif isinstance(data, set):
            self.keys = list(range(len(data)))
            self.title += _("Set")
            self._data = list(data)
        elif isinstance(data, dict):
            try:
                self.keys = sorted(list(data.keys()), key=natsort)
            except TypeError:
                # This is necessary to display dictionaries with mixed
                # types as keys.
                # Fixes spyder-ide/spyder#13481
                self.keys = list(data.keys())
            self.title += _("Dictionary")
            if not self.names:
                self.header0 = _("Key")
        else:
            self.keys = get_object_attrs(data)
            self._data = data = self.showndata = ProxyObject(data)
            if not self.names:
                self.header0 = _("Attribute")
        if not isinstance(self._data, ProxyObject):
            if len(self.keys) > 1:
                elements = _("elements")
            else:
                elements = _("element")
            self.title += (' (' + str(len(self.keys)) + ' ' + elements + ')')
        else:
            data_type = get_type_string(data)
            self.title += data_type
        self.total_rows = len(self.keys)
        if self.total_rows > LARGE_NROWS:
            self.rows_loaded = ROWS_TO_LOAD
        else:
            self.rows_loaded = self.total_rows
        self.sig_setting_data.emit()
        self.set_size_and_type()
        if len(self.keys):
            # Needed to update search scores when
            # adding values to the namespace
            self.update_search_letters()
        self.reset()

    def set_size_and_type(self, start=None, stop=None):
        data = self._data

        if start is None and stop is None:
            start = 0
            stop = self.rows_loaded
            fetch_more = False
        else:
            fetch_more = True

        # Ignore pandas warnings that certain attributes are deprecated
        # and will be removed, since they will only be accessed if they exist.
        with warnings.catch_warnings():
            warnings.filterwarnings(
                "ignore", message=(r"^\w+\.\w+ is deprecated and "
                                   "will be removed in a future version"))
            if self.remote:
                sizes = [data[self.keys[index]]['size']
                         for index in range(start, stop)]
                types = [data[self.keys[index]]['type']
                         for index in range(start, stop)]
            else:
                sizes = [get_size(data[self.keys[index]])
                         for index in range(start, stop)]
                types = [get_human_readable_type(data[self.keys[index]])
                         for index in range(start, stop)]

        if fetch_more:
            self.sizes = self.sizes + sizes
            self.types = self.types + types
        else:
            self.sizes = sizes
            self.types = types

    def load_all(self):
        """Load all the data."""
        self.fetchMore(number_to_fetch=self.total_rows)

    def sort(self, column, order=Qt.AscendingOrder):
        """Overriding sort method"""

        def all_string(listlike):
            return all([isinstance(x, str) for x in listlike])

        reverse = (order == Qt.DescendingOrder)
        sort_key = natsort if all_string(self.keys) else None

        if column == 0:
            self.sizes = sort_against(self.sizes, self.keys,
                                      reverse=reverse,
                                      sort_key=natsort)
            self.types = sort_against(self.types, self.keys,
                                      reverse=reverse,
                                      sort_key=natsort)
            try:
                self.keys.sort(reverse=reverse, key=sort_key)
            except:
                pass
        elif column == 1:
            self.keys[:self.rows_loaded] = sort_against(self.keys,
                                                        self.types,
                                                        reverse=reverse)
            self.sizes = sort_against(self.sizes, self.types, reverse=reverse)
            try:
                self.types.sort(reverse=reverse)
            except:
                pass
        elif column == 2:
            self.keys[:self.rows_loaded] = sort_against(self.keys,
                                                        self.sizes,
                                                        reverse=reverse)
            self.types = sort_against(self.types, self.sizes, reverse=reverse)
            try:
                self.sizes.sort(reverse=reverse)
            except:
                pass
        elif column in [3, 4]:
            values = [self._data[key] for key in self.keys]
            self.keys = sort_against(self.keys, values, reverse=reverse)
            self.sizes = sort_against(self.sizes, values, reverse=reverse)
            self.types = sort_against(self.types, values, reverse=reverse)
        self.beginResetModel()
        self.endResetModel()

    def columnCount(self, qindex=QModelIndex()):
        """Array column number"""
        if self._parent.proxy_model:
            return 5
        else:
            return 4

    def rowCount(self, index=QModelIndex()):
        """Array row number"""
        if self.total_rows <= self.rows_loaded:
            return self.total_rows
        else:
            return self.rows_loaded

    def canFetchMore(self, index=QModelIndex()):
        if self.total_rows > self.rows_loaded:
            return True
        else:
            return False

    def fetchMore(self, index=QModelIndex(), number_to_fetch=None):
        # fetch more data
        reminder = self.total_rows - self.rows_loaded
        if reminder <= 0:
            # Everything is loaded
            return
        if number_to_fetch is not None:
            items_to_fetch = min(reminder, number_to_fetch)
        else:
            items_to_fetch = min(reminder, ROWS_TO_LOAD)
        self.set_size_and_type(self.rows_loaded,
                               self.rows_loaded + items_to_fetch)
        self.beginInsertRows(QModelIndex(), self.rows_loaded,
                             self.rows_loaded + items_to_fetch - 1)
        self.rows_loaded += items_to_fetch
        self.endInsertRows()

    def get_index_from_key(self, key):
        try:
            return self.createIndex(self.keys.index(key), 0)
        except (RuntimeError, ValueError):
            return QModelIndex()

    def get_key(self, index):
        """Return current key"""
        return self.keys[index.row()]

    def get_value(self, index):
        """Return current value"""
        if index.column() == 0:
            return self.keys[ index.row() ]
        elif index.column() == 1:
            return self.types[ index.row() ]
        elif index.column() == 2:
            return self.sizes[ index.row() ]
        else:
            return self._data[ self.keys[index.row()] ]

    def get_bgcolor(self, index):
        """Background color depending on value"""
        if index.column() == 0:
            color = QColor(Qt.lightGray)
            color.setAlphaF(.05)
        elif index.column() < 3:
            color = QColor(Qt.lightGray)
            color.setAlphaF(.2)
        else:
            color = QColor(Qt.lightGray)
            color.setAlphaF(.3)
        return color

    def update_search_letters(self, text=""):
        """Update search letters with text input in search box."""
        self.letters = text
        names = [str(key) for key in self.keys]
        results = get_search_scores(text, names, template='<b>{0}</b>')
        if results:
            self.normal_text, _, self.scores = zip(*results)
            self.reset()

    def row_key(self, row_num):
        """
        Get row name based on model index.
        Needed for the custom proxy model.
        """
        return self.keys[row_num]

    def row_type(self, row_num):
        """
        Get row type based on model index.
        Needed for the custom proxy model.
        """
        return self.types[row_num]

    def data(self, index, role=Qt.DisplayRole):
        """Cell content"""
        if not index.isValid():
            return to_qvariant()
        value = self.get_value(index)
        if index.column() == 4 and role == Qt.DisplayRole:
            # TODO: Check the effect of not hiding the column
            # Treating search scores as a table column simplifies the
            # sorting once a score for a specific string in the finder
            # has been defined. This column however should always remain
            # hidden.
            return to_qvariant(self.scores[index.row()])
        if index.column() == 3 and self.remote:
            value = value['view']
        if index.column() == 3:
            display = value_to_display(value, minmax=self.minmax)
        else:
            if is_type_text_string(value):
                display = to_text_string(value, encoding="utf-8")
            elif not isinstance(
                value, NUMERIC_TYPES + get_numeric_numpy_types()
            ):
                display = to_text_string(value)
            else:
                display = value
        if role == Qt.UserRole:
            if isinstance(value, NUMERIC_TYPES + get_numeric_numpy_types()):
                return to_qvariant(value)
            else:
                return to_qvariant(display)
        elif role == Qt.DisplayRole:
            return to_qvariant(display)
        elif role == Qt.EditRole:
            return to_qvariant(value_to_display(value))
        elif role == Qt.TextAlignmentRole:
            if index.column() == 3:
                if len(display.splitlines()) < 3:
                    return to_qvariant(int(Qt.AlignLeft|Qt.AlignVCenter))
                else:
                    return to_qvariant(int(Qt.AlignLeft|Qt.AlignTop))
            else:
                return to_qvariant(int(Qt.AlignLeft|Qt.AlignVCenter))
        elif role == Qt.BackgroundColorRole:
            return to_qvariant( self.get_bgcolor(index) )
        elif role == Qt.FontRole:
            return to_qvariant(get_font(font_size_delta=DEFAULT_SMALL_DELTA))
        return to_qvariant()

    def headerData(self, section, orientation, role=Qt.DisplayRole):
        """Overriding method headerData"""
        if role != Qt.DisplayRole:
            return to_qvariant()
        i_column = int(section)
        if orientation == Qt.Horizontal:
            headers = (self.header0, _("Type"), _("Size"), _("Value"),
                       _("Score"))
            return to_qvariant( headers[i_column] )
        else:
            return to_qvariant()

    def flags(self, index):
        """Overriding method flags"""
        # This method was implemented in CollectionsModel only, but to enable
        # tuple exploration (even without editing), this method was moved here
        if not index.isValid():
            return Qt.ItemIsEnabled
        return Qt.ItemFlags(int(QAbstractTableModel.flags(self, index) |
                                Qt.ItemIsEditable))

    def reset(self):
        self.beginResetModel()
        self.endResetModel()


class CollectionsModel(ReadOnlyCollectionsModel):
    """Collections Table Model"""

    def set_value(self, index, value):
        """Set value"""
        self._data[ self.keys[index.row()] ] = value
        self.showndata[ self.keys[index.row()] ] = value
        self.sizes[index.row()] = get_size(value)
        self.types[index.row()] = get_human_readable_type(value)
        self.sig_setting_data.emit()

    def type_to_color(self, python_type, numpy_type):
        """Get the color that corresponds to a Python type."""
        # Color for unknown types
        color = SpyderPalette.GROUP_12

        if numpy_type != 'Unknown':
            if numpy_type == 'Array':
                color = SpyderPalette.GROUP_9
            elif numpy_type == 'Scalar':
                color = SpyderPalette.GROUP_2
        elif python_type == 'bool':
            color = SpyderPalette.GROUP_1
        elif python_type in ['int', 'float', 'complex']:
            color = SpyderPalette.GROUP_2
        elif python_type in ['str', 'unicode']:
            color = SpyderPalette.GROUP_3
        elif 'datetime' in python_type:
            color = SpyderPalette.GROUP_4
        elif python_type == 'list':
            color = SpyderPalette.GROUP_5
        elif python_type == 'set':
            color = SpyderPalette.GROUP_6
        elif python_type == 'tuple':
            color = SpyderPalette.GROUP_7
        elif python_type == 'dict':
            color = SpyderPalette.GROUP_8
        elif python_type in ['MaskedArray', 'Matrix', 'NDArray']:
            color = SpyderPalette.GROUP_9
        elif (python_type in ['DataFrame', 'Series'] or
                'Index' in python_type):
            color = SpyderPalette.GROUP_10
        elif python_type == 'PIL.Image.Image':
            color = SpyderPalette.GROUP_11
        else:
            color = SpyderPalette.GROUP_12

        return color

    def get_bgcolor(self, index):
        """Background color depending on value."""
        value = self.get_value(index)
        if index.column() < 3:
            color = ReadOnlyCollectionsModel.get_bgcolor(self, index)
        else:
            if self.remote:
                python_type = value['python_type']
                numpy_type = value['numpy_type']
            else:
                python_type = get_type_string(value)
                numpy_type = get_numpy_type_string(value)
            color_name = self.type_to_color(python_type, numpy_type)
            color = QColor(color_name)
            color.setAlphaF(0.5)
        return color

    def setData(self, index, value, role=Qt.EditRole):
        """Cell content change"""
        if not index.isValid():
            return False
        if index.column() < 3:
            return False
        value = display_to_value(value, self.get_value(index),
                                 ignore_errors=True)
        self.set_value(index, value)
        self.dataChanged.emit(index, index)
        return True


class BaseHeaderView(QHeaderView):
    """
    A header view for the BaseTableView that emits a signal when the width of
    one of its sections is resized by the user.
    """
    sig_user_resized_section = Signal(int, int, int)

    def __init__(self, parent=None):
        super(BaseHeaderView, self).__init__(Qt.Horizontal, parent)
        self._handle_section_is_pressed = False
        self.sectionResized.connect(self.sectionResizeEvent)
        # Needed to enable sorting by column
        # See spyder-ide/spyder#9835
        self.setSectionsClickable(True)

    def mousePressEvent(self, e):
        super(BaseHeaderView, self).mousePressEvent(e)
        self._handle_section_is_pressed = (self.cursor().shape() ==
                                           Qt.SplitHCursor)

    def mouseReleaseEvent(self, e):
        super(BaseHeaderView, self).mouseReleaseEvent(e)
        self._handle_section_is_pressed = False

    def sectionResizeEvent(self, logicalIndex, oldSize, newSize):
        if self._handle_section_is_pressed:
            self.sig_user_resized_section.emit(logicalIndex, oldSize, newSize)


class BaseTableView(QTableView, SpyderConfigurationAccessor):
    """Base collection editor table view"""
    CONF_SECTION = 'variable_explorer'

    sig_files_dropped = Signal(list)
    redirect_stdio = Signal(bool)
    sig_free_memory_requested = Signal()
    sig_editor_creation_started = Signal()
    sig_editor_shown = Signal()

    def __init__(self, parent):
        super().__init__(parent=parent)

        self.array_filename = None
        self.menu = None
        self.menu_actions = []
        self.empty_ws_menu = None
        self.paste_action = None
        self.copy_action = None
        self.edit_action = None
        self.plot_action = None
        self.hist_action = None
        self.imshow_action = None
        self.save_array_action = None
        self.insert_action = None
        self.insert_action_above = None
        self.insert_action_below = None
        self.remove_action = None
        self.minmax_action = None
        self.rename_action = None
        self.duplicate_action = None
        self.view_action = None
        self.delegate = None
        self.proxy_model = None
        self.source_model = None
        self.setAcceptDrops(True)
        self.automatic_column_width = True
        self.setHorizontalHeader(BaseHeaderView(parent=self))
        self.horizontalHeader().sig_user_resized_section.connect(
            self.user_resize_columns)

    def setup_table(self):
        """Setup table"""
        self.horizontalHeader().setStretchLastSection(True)
        self.horizontalHeader().setSectionsMovable(True)
        self.adjust_columns()
        # Sorting columns
        self.setSortingEnabled(True)
        self.sortByColumn(0, Qt.AscendingOrder)
        self.selectionModel().selectionChanged.connect(self.refresh_menu)

    def setup_menu(self):
        """Setup context menu"""
        resize_action = create_action(self, _("Resize rows to contents"),
                                      icon=ima.icon('collapse_row'),
                                      triggered=self.resizeRowsToContents)
        resize_columns_action = create_action(
            self,
            _("Resize columns to contents"),
            icon=ima.icon('collapse_column'),
            triggered=self.resize_column_contents)
        self.paste_action = create_action(self, _("Paste"),
                                          icon=ima.icon('editpaste'),
                                          triggered=self.paste)
        self.copy_action = create_action(self, _("Copy"),
                                         icon=ima.icon('editcopy'),
                                         triggered=self.copy)
        self.edit_action = create_action(self, _("Edit"),
                                         icon=ima.icon('edit'),
                                         triggered=self.edit_item)
        self.plot_action = create_action(self, _("Plot"),
                                    icon=ima.icon('plot'),
                                    triggered=lambda: self.plot_item('plot'))
        self.plot_action.setVisible(False)
        self.hist_action = create_action(self, _("Histogram"),
                                    icon=ima.icon('hist'),
                                    triggered=lambda: self.plot_item('hist'))
        self.hist_action.setVisible(False)
        self.imshow_action = create_action(self, _("Show image"),
                                           icon=ima.icon('imshow'),
                                           triggered=self.imshow_item)
        self.imshow_action.setVisible(False)
        self.save_array_action = create_action(self, _("Save array"),
                                               icon=ima.icon('filesave'),
                                               triggered=self.save_array)
        self.save_array_action.setVisible(False)
        self.insert_action = create_action(
            self, _("Insert"),
            icon=ima.icon('insert'),
            triggered=lambda: self.insert_item(below=False)
        )
        self.insert_action_above = create_action(
            self, _("Insert above"),
            icon=ima.icon('insert_above'),
            triggered=lambda: self.insert_item(below=False)
        )
        self.insert_action_below = create_action(
            self, _("Insert below"),
            icon=ima.icon('insert_below'),
            triggered=lambda: self.insert_item(below=True)
        )
        self.remove_action = create_action(self, _("Remove"),
                                           icon=ima.icon('editdelete'),
                                           triggered=self.remove_item)
        self.rename_action = create_action(self, _("Rename"),
                                           icon=ima.icon('rename'),
                                           triggered=self.rename_item)
        self.duplicate_action = create_action(self, _("Duplicate"),
                                              icon=ima.icon('edit_add'),
                                              triggered=self.duplicate_item)
        self.view_action = create_action(
            self,
            _("View with the Object Explorer"),
            icon=ima.icon('outline_explorer'),
            triggered=self.view_item)

        menu = QMenu(self)
        self.menu_actions = [
            self.edit_action,
            self.copy_action,
            self.paste_action,
            self.rename_action,
            self.remove_action,
            self.save_array_action,
            MENU_SEPARATOR,
            self.insert_action,
            self.insert_action_above,
            self.insert_action_below,
            self.duplicate_action,
            MENU_SEPARATOR,
            self.view_action,
            self.plot_action,
            self.hist_action,
            self.imshow_action,
            MENU_SEPARATOR,
            resize_action,
            resize_columns_action
        ]
        add_actions(menu, self.menu_actions)

        self.empty_ws_menu = QMenu(self)
        add_actions(
            self.empty_ws_menu,
            [self.insert_action, self.paste_action]
        )

        return menu


    # ------ Remote/local API -------------------------------------------------
    def remove_values(self, keys):
        """Remove values from data"""
        raise NotImplementedError

    def copy_value(self, orig_key, new_key):
        """Copy value"""
        raise NotImplementedError

    def new_value(self, key, value):
        """Create new value in data"""
        raise NotImplementedError

    def is_list(self, key):
        """Return True if variable is a list, a set or a tuple"""
        raise NotImplementedError

    def get_len(self, key):
        """Return sequence length"""
        raise NotImplementedError

    def is_array(self, key):
        """Return True if variable is a numpy array"""
        raise NotImplementedError

    def is_image(self, key):
        """Return True if variable is a PIL.Image image"""
        raise NotImplementedError

    def is_dict(self, key):
        """Return True if variable is a dictionary"""
        raise NotImplementedError

    def get_array_shape(self, key):
        """Return array's shape"""
        raise NotImplementedError

    def get_array_ndim(self, key):
        """Return array's ndim"""
        raise NotImplementedError

    def oedit(self, key):
        """Edit item"""
        raise NotImplementedError

    def plot(self, key, funcname):
        """Plot item"""
        raise NotImplementedError

    def imshow(self, key):
        """Show item's image"""
        raise NotImplementedError

    def show_image(self, key):
        """Show image (item is a PIL image)"""
        raise NotImplementedError
    #--------------------------------------------------------------------------

    def refresh_menu(self):
        """Refresh context menu"""
        index = self.currentIndex()
        data = self.source_model.get_data()
        is_list_instance = isinstance(data, list)
        is_dict_instance = isinstance(data, dict)

        def indexes_in_same_row():
            indexes = self.selectedIndexes()
            if len(indexes) > 1:
                rows = [idx.row() for idx in indexes]
                return len(set(rows)) == 1
            else:
                return True

        # Enable/disable actions
        condition_edit = (
            (not isinstance(data, (tuple, set))) and
            index.isValid() and
            (len(self.selectedIndexes()) > 0) and
            indexes_in_same_row() and
            not self.readonly
        )
        self.edit_action.setEnabled(condition_edit)
        self.insert_action_above.setEnabled(condition_edit)
        self.insert_action_below.setEnabled(condition_edit)
        self.duplicate_action.setEnabled(condition_edit)
        self.rename_action.setEnabled(condition_edit)
        self.plot_action.setEnabled(condition_edit)
        self.hist_action.setEnabled(condition_edit)
        self.imshow_action.setEnabled(condition_edit)
        self.save_array_action.setEnabled(condition_edit)

        condition_select = (
            index.isValid() and
            (len(self.selectedIndexes()) > 0)
        )
        self.view_action.setEnabled(
            condition_select and indexes_in_same_row())
        self.copy_action.setEnabled(condition_select)

        condition_remove = (
            (not isinstance(data, (tuple, set))) and
            index.isValid() and
            (len(self.selectedIndexes()) > 0) and
            not self.readonly
        )
        self.remove_action.setEnabled(condition_remove)

        self.insert_action.setEnabled(
            is_dict_instance and not self.readonly)
        self.paste_action.setEnabled(
            is_dict_instance and not self.readonly)

        # Hide/show actions
        if index.isValid():
            if self.proxy_model:
                key = self.proxy_model.get_key(index)
            else:
                key = self.source_model.get_key(index)
            is_list = self.is_list(key)
            is_array = self.is_array(key) and self.get_len(key) != 0
            condition_plot = (is_array and len(self.get_array_shape(key)) <= 2)
            condition_hist = (is_array and self.get_array_ndim(key) == 1)
            condition_imshow = condition_plot and self.get_array_ndim(key) == 2
            condition_imshow = condition_imshow or self.is_image(key)
        else:
            is_array = condition_plot = condition_imshow = is_list \
                     = condition_hist = False

        self.plot_action.setVisible(condition_plot or is_list)
        self.hist_action.setVisible(condition_hist or is_list)
        self.insert_action.setVisible(is_dict_instance)
        self.insert_action_above.setVisible(is_list_instance)
        self.insert_action_below.setVisible(is_list_instance)
        self.rename_action.setVisible(is_dict_instance)
        self.paste_action.setVisible(is_dict_instance)
        self.imshow_action.setVisible(condition_imshow)
        self.save_array_action.setVisible(is_array)

    def resize_column_contents(self):
        """Resize columns to contents."""
        self.automatic_column_width = True
        self.adjust_columns()

    def user_resize_columns(self, logical_index, old_size, new_size):
        """Handle the user resize action."""
        self.automatic_column_width = False

    def adjust_columns(self):
        """Resize two first columns to contents"""
        if self.automatic_column_width:
            for col in range(3):
                self.resizeColumnToContents(col)

    def set_data(self, data):
        """Set table data"""
        if data is not None:
            self.source_model.set_data(data, self.dictfilter)
            self.source_model.reset()
            self.sortByColumn(0, Qt.AscendingOrder)

    def mousePressEvent(self, event):
        """Reimplement Qt method"""
        if event.button() != Qt.LeftButton:
            QTableView.mousePressEvent(self, event)
            return
        index_clicked = self.indexAt(event.pos())
        if index_clicked.isValid():
            if index_clicked == self.currentIndex() \
               and index_clicked in self.selectedIndexes():
                self.clearSelection()
            else:
                QTableView.mousePressEvent(self, event)
        else:
            self.clearSelection()
            event.accept()

    def mouseDoubleClickEvent(self, event):
        """Reimplement Qt method"""
        index_clicked = self.indexAt(event.pos())
        if index_clicked.isValid():
            row = index_clicked.row()
            # TODO: Remove hard coded "Value" column number (3 here)
            index_clicked = index_clicked.child(row, 3)
            self.edit(index_clicked)
        else:
            event.accept()

    def keyPressEvent(self, event):
        """Reimplement Qt methods"""
        if event.key() == Qt.Key_Delete:
            self.remove_item()
        elif event.key() == Qt.Key_F2:
            self.rename_item()
        elif event == QKeySequence.Copy:
            self.copy()
        elif event == QKeySequence.Paste:
            self.paste()
        else:
            QTableView.keyPressEvent(self, event)

    def contextMenuEvent(self, event):
        """Reimplement Qt method"""
        if self.source_model.showndata:
            self.refresh_menu()
            self.menu.popup(event.globalPos())
            event.accept()
        else:
            self.empty_ws_menu.popup(event.globalPos())
            event.accept()

    def dragEnterEvent(self, event):
        """Allow user to drag files"""
        if mimedata2url(event.mimeData()):
            event.accept()
        else:
            event.ignore()

    def dragMoveEvent(self, event):
        """Allow user to move files"""
        if mimedata2url(event.mimeData()):
            event.setDropAction(Qt.CopyAction)
            event.accept()
        else:
            event.ignore()

    def dropEvent(self, event):
        """Allow user to drop supported files"""
        urls = mimedata2url(event.mimeData())
        if urls:
            event.setDropAction(Qt.CopyAction)
            event.accept()
            self.sig_files_dropped.emit(urls)
        else:
            event.ignore()

    def _deselect_index(self, index):
        """
        Deselect index after any operation that adds or removes rows to/from
        the editor.

        Notes
        -----
        * This avoids showing the wrong buttons in the editor's toolbar when
          the operation is completed.
        * Also, if we leave something selected, then the next operation won't
          introduce the item in the expected row. That's why we need to force
          users to select a row again after this.
        """
        self.selectionModel().select(index, QItemSelectionModel.Select)
        self.selectionModel().select(index, QItemSelectionModel.Deselect)

    @Slot()
    def edit_item(self):
        """Edit item"""
        index = self.currentIndex()
        if not index.isValid():
            return
        # TODO: Remove hard coded "Value" column number (3 here)
        self.edit(index.child(index.row(), 3))

    @Slot()
    def remove_item(self, force=False):
        """Remove item"""
        current_index = self.currentIndex()
        indexes = self.selectedIndexes()

        if not indexes:
            return

        for index in indexes:
            if not index.isValid():
                return

        if not force:
            one = _("Do you want to remove the selected item?")
            more = _("Do you want to remove all selected items?")
            answer = QMessageBox.question(self, _("Remove"),
                                          one if len(indexes) == 1 else more,
                                          QMessageBox.Yes | QMessageBox.No)

        if force or answer == QMessageBox.Yes:
            if self.proxy_model:
                idx_rows = unsorted_unique(
                    [self.proxy_model.mapToSource(idx).row()
                     for idx in indexes])
            else:
                idx_rows = unsorted_unique([idx.row() for idx in indexes])
            keys = [self.source_model.keys[idx_row] for idx_row in idx_rows]
            self.remove_values(keys)

        # This avoids a segfault in our tests that doesn't happen when
        # removing items manually.
        if not running_under_pytest():
            self._deselect_index(current_index)

    def copy_item(self, erase_original=False, new_name=None):
        """Copy item"""
        current_index = self.currentIndex()
        indexes = self.selectedIndexes()

        if not indexes:
            return

        if self.proxy_model:
            idx_rows = unsorted_unique(
                [self.proxy_model.mapToSource(idx).row() for idx in indexes])
        else:
            idx_rows = unsorted_unique([idx.row() for idx in indexes])

        if len(idx_rows) > 1 or not indexes[0].isValid():
            return

        orig_key = self.source_model.keys[idx_rows[0]]
        if erase_original:
            if not isinstance(orig_key, str):
                QMessageBox.warning(
                    self,
                    _("Warning"),
                    _("You can only rename keys that are strings")
                )
                return

            title = _('Rename')
            field_text = _('New variable name:')
        else:
            title = _('Duplicate')
            field_text = _('Variable name:')

        data = self.source_model.get_data()
        if isinstance(data, (list, set)):
            new_key, valid = len(data), True
        elif new_name is not None:
            new_key, valid = new_name, True
        else:
            new_key, valid = QInputDialog.getText(self, title, field_text,
                                                  QLineEdit.Normal, orig_key)

        if valid and to_text_string(new_key):
            new_key = try_to_eval(to_text_string(new_key))
            if new_key == orig_key:
                return
            self.copy_value(orig_key, new_key)
            if erase_original:
                self.remove_values([orig_key])

        self._deselect_index(current_index)

    @Slot()
    def duplicate_item(self):
        """Duplicate item"""
        self.copy_item()

    @Slot()
    def rename_item(self, new_name=None):
        """Rename item"""
        self.copy_item(erase_original=True, new_name=new_name)

    @Slot()
    def insert_item(self, below=True):
        """Insert item"""
        index = self.currentIndex()
        if not index.isValid():
            row = self.source_model.rowCount()
        else:
            if self.proxy_model:
                if below:
                    row = self.proxy_model.mapToSource(index).row() + 1
                else:
                    row = self.proxy_model.mapToSource(index).row()
            else:
                if below:
                    row = index.row() + 1
                else:
                    row = index.row()
        data = self.source_model.get_data()

        if isinstance(data, list):
            key = row
            data.insert(row, '')
        elif isinstance(data, dict):
            key, valid = QInputDialog.getText(self, _('Insert'), _('Key:'),
                                              QLineEdit.Normal)
            if valid and to_text_string(key):
                key = try_to_eval(to_text_string(key))
            else:
                return
        else:
            return

        value, valid = QInputDialog.getText(self, _('Insert'), _('Value:'),
                                            QLineEdit.Normal)

        if valid and to_text_string(value):
            self.new_value(key, try_to_eval(to_text_string(value)))

    @Slot()
    def view_item(self):
        """View item with the Object Explorer"""
        index = self.currentIndex()
        if not index.isValid():
            return
        # TODO: Remove hard coded "Value" column number (3 here)
        index = index.child(index.row(), 3)
        self.delegate.createEditor(self, None, index, object_explorer=True)

    def __prepare_plot(self):
        try:
            import guiqwt.pyplot   #analysis:ignore
            return True
        except:
            try:
                if 'matplotlib' not in sys.modules:
                    import matplotlib
                return True
            except Exception:
                QMessageBox.warning(self, _("Import error"),
                                    _("Please install <b>matplotlib</b>"
                                      " or <b>guiqwt</b>."))

    def plot_item(self, funcname):
        """Plot item"""
        index = self.currentIndex()
        if self.__prepare_plot():
            if self.proxy_model:
                key = self.source_model.get_key(
                    self.proxy_model.mapToSource(index))
            else:
                key = self.source_model.get_key(index)
            try:
                self.plot(key, funcname)
            except (ValueError, TypeError) as error:
                QMessageBox.critical(self, _( "Plot"),
                                     _("<b>Unable to plot data.</b>"
                                       "<br><br>Error message:<br>%s"
                                       ) % str(error))

    @Slot()
    def imshow_item(self):
        """Imshow item"""
        index = self.currentIndex()
        if self.__prepare_plot():
            if self.proxy_model:
                key = self.source_model.get_key(
                    self.proxy_model.mapToSource(index))
            else:
                key = self.source_model.get_key(index)
            try:
                if self.is_image(key):
                    self.show_image(key)
                else:
                    self.imshow(key)
            except (ValueError, TypeError) as error:
                QMessageBox.critical(self, _( "Plot"),
                                     _("<b>Unable to show image.</b>"
                                       "<br><br>Error message:<br>%s"
                                       ) % str(error))

    @Slot()
    def save_array(self):
        """Save array"""
        title = _( "Save array")
        if self.array_filename is None:
            self.array_filename = getcwd_or_home()
        self.redirect_stdio.emit(False)
        filename, _selfilter = getsavefilename(self, title,
                                               self.array_filename,
                                               _("NumPy arrays")+" (*.npy)")
        self.redirect_stdio.emit(True)
        if filename:
            self.array_filename = filename
            data = self.delegate.get_value( self.currentIndex() )
            try:
                import numpy as np
                np.save(self.array_filename, data)
            except Exception as error:
                QMessageBox.critical(self, title,
                                     _("<b>Unable to save array</b>"
                                       "<br><br>Error message:<br>%s"
                                       ) % str(error))

    @Slot()
    def copy(self):
        """Copy text to clipboard"""
        clipboard = QApplication.clipboard()
        clipl = []
        for idx in self.selectedIndexes():
            if not idx.isValid():
                continue
            obj = self.delegate.get_value(idx)
            # Check if we are trying to copy a numpy array, and if so make sure
            # to copy the whole thing in a tab separated format
            if (isinstance(obj, (np.ndarray, np.ma.MaskedArray)) and
                    np.ndarray is not FakeObject):
                if PY3:
                    output = io.BytesIO()
                else:
                    output = io.StringIO()
                try:
                    np.savetxt(output, obj, delimiter='\t')
                except Exception:
                    QMessageBox.warning(self, _("Warning"),
                                        _("It was not possible to copy "
                                          "this array"))
                    return
                obj = output.getvalue().decode('utf-8')
                output.close()
            elif (isinstance(obj, (pd.DataFrame, pd.Series)) and
                    pd.DataFrame is not FakeObject):
                output = io.StringIO()
                try:
                    obj.to_csv(output, sep='\t', index=True, header=True)
                except Exception:
                    QMessageBox.warning(self, _("Warning"),
                                        _("It was not possible to copy "
                                          "this dataframe"))
                    return
                if PY3:
                    obj = output.getvalue()
                else:
                    obj = output.getvalue().decode('utf-8')
                output.close()
            elif is_binary_string(obj):
                obj = to_text_string(obj, 'utf8')
            else:
                obj = to_text_string(obj)
            clipl.append(obj)
        clipboard.setText('\n'.join(clipl))

    def import_from_string(self, text, title=None):
        """Import data from string"""
        data = self.source_model.get_data()
        # Check if data is a dict
        if not hasattr(data, "keys"):
            return
        editor = ImportWizard(
            self, text, title=title, contents_title=_("Clipboard contents"),
            varname=fix_reference_name("data", blacklist=list(data.keys())))
        if editor.exec_():
            var_name, clip_data = editor.get_data()
            self.new_value(var_name, clip_data)

    @Slot()
    def paste(self):
        """Import text/data/code from clipboard"""
        clipboard = QApplication.clipboard()
        cliptext = ''
        if clipboard.mimeData().hasText():
            cliptext = to_text_string(clipboard.text())
        if cliptext.strip():
            self.import_from_string(cliptext, title=_("Import from clipboard"))
        else:
            QMessageBox.warning(self, _( "Empty clipboard"),
                                _("Nothing to be imported from clipboard."))


class CollectionsEditorTableView(BaseTableView):
    """CollectionsEditor table view"""
    def __init__(self, parent, data, readonly=False, title="",
                 names=False):
        BaseTableView.__init__(self, parent)
        self.dictfilter = None
        self.readonly = readonly or isinstance(data, (tuple, set))
        CollectionsModelClass = (ReadOnlyCollectionsModel if self.readonly
                                 else CollectionsModel)
        self.source_model = CollectionsModelClass(
            self,
            data,
            title,
            names=names,
            minmax=self.get_conf('minmax')
        )
        self.model = self.source_model
        self.setModel(self.source_model)
        self.delegate = CollectionsDelegate(self)
        self.setItemDelegate(self.delegate)

        self.setup_table()
        self.menu = self.setup_menu()
        if isinstance(data, set):
            self.horizontalHeader().hideSection(0)

    #------ Remote/local API --------------------------------------------------
    def remove_values(self, keys):
        """Remove values from data"""
        data = self.source_model.get_data()
        for key in sorted(keys, reverse=True):
            data.pop(key)
        self.set_data(data)

    def copy_value(self, orig_key, new_key):
        """Copy value"""
        data = self.source_model.get_data()
        if isinstance(data, list):
            data.append(data[orig_key])
        if isinstance(data, set):
            data.add(data[orig_key])
        else:
            data[new_key] = data[orig_key]
        self.set_data(data)

    def new_value(self, key, value):
        """Create new value in data"""
        index = self.currentIndex()
        data = self.source_model.get_data()
        data[key] = value
        self.set_data(data)
        self._deselect_index(index)

    def is_list(self, key):
        """Return True if variable is a list or a tuple"""
        data = self.source_model.get_data()
        return isinstance(data[key], (tuple, list))

    def is_set(self, key):
        """Return True if variable is a set"""
        data = self.source_model.get_data()
        return isinstance(data[key], set)

    def get_len(self, key):
        """Return sequence length"""
        data = self.source_model.get_data()
        return len(data[key])

    def is_array(self, key):
        """Return True if variable is a numpy array"""
        data = self.source_model.get_data()
        return isinstance(data[key], (np.ndarray, np.ma.MaskedArray))

    def is_image(self, key):
        """Return True if variable is a PIL.Image image"""
        data = self.source_model.get_data()
        return isinstance(data[key], PIL.Image.Image)

    def is_dict(self, key):
        """Return True if variable is a dictionary"""
        data = self.source_model.get_data()
        return isinstance(data[key], dict)

    def get_array_shape(self, key):
        """Return array's shape"""
        data = self.source_model.get_data()
        return data[key].shape

    def get_array_ndim(self, key):
        """Return array's ndim"""
        data = self.source_model.get_data()
        return data[key].ndim

    def oedit(self, key):
        """Edit item"""
        data = self.source_model.get_data()
        from spyder.plugins.variableexplorer.widgets.objecteditor import (
                oedit)
        oedit(data[key])

    def plot(self, key, funcname):
        """Plot item"""
        data = self.source_model.get_data()
        import spyder.pyplot as plt
        plt.figure()
        getattr(plt, funcname)(data[key])
        plt.show()

    def imshow(self, key):
        """Show item's image"""
        data = self.source_model.get_data()
        import spyder.pyplot as plt
        plt.figure()
        plt.imshow(data[key])
        plt.show()

    def show_image(self, key):
        """Show image (item is a PIL image)"""
        data = self.source_model.get_data()
        data[key].show()
    #--------------------------------------------------------------------------

    def set_filter(self, dictfilter=None):
        """Set table dict filter"""
        self.dictfilter = dictfilter


class CollectionsEditorWidget(QWidget):
    """Dictionary Editor Widget"""
    def __init__(self, parent, data, readonly=False, title="", remote=False):
        QWidget.__init__(self, parent)
        if remote:
            self.editor = RemoteCollectionsEditorTableView(self, data, readonly)
        else:
            self.editor = CollectionsEditorTableView(self, data, readonly,
                                                     title)

        toolbar = SpyderToolbar(parent=None, title='Editor toolbar')
        toolbar.setStyleSheet(str(PANES_TOOLBAR_STYLESHEET))

        for item in self.editor.menu_actions:
            if item is not None:
                toolbar.addAction(item)

        # Update the toolbar actions state
        self.editor.refresh_menu()
        layout = QVBoxLayout()
        layout.addWidget(toolbar)
        layout.addWidget(self.editor)
        self.setLayout(layout)

    def set_data(self, data):
        """Set DictEditor data"""
        self.editor.set_data(data)

    def get_title(self):
        """Get model title"""
        return self.editor.source_model.title


class CollectionsEditor(BaseDialog):
    """Collections Editor Dialog"""
    def __init__(self, parent=None):
        super().__init__(parent)

        # Destroying the C++ object right after closing the dialog box,
        # otherwise it may be garbage-collected in another QThread
        # (e.g. the editor's analysis thread in Spyder), thus leading to
        # a segmentation fault on UNIX or an application crash on Windows
        self.setAttribute(Qt.WA_DeleteOnClose)

        self.data_copy = None
        self.widget = None
        self.btn_save_and_close = None
        self.btn_close = None

    def setup(self, data, title='', readonly=False, remote=False,
              icon=None, parent=None):
        """Setup editor."""
        if isinstance(data, (dict, set)):
            # dictionary, set
            self.data_copy = data.copy()
            datalen = len(data)
        elif isinstance(data, (tuple, list)):
            # list, tuple
            self.data_copy = data[:]
            datalen = len(data)
        else:
            # unknown object
            import copy
            try:
                self.data_copy = copy.deepcopy(data)
            except NotImplementedError:
                self.data_copy = copy.copy(data)
            except (TypeError, AttributeError):
                readonly = True
                self.data_copy = data
            datalen = len(get_object_attrs(data))

        # If the copy has a different type, then do not allow editing, because
        # this would change the type after saving; cf. spyder-ide/spyder#6936.
        if type(self.data_copy) != type(data):
            readonly = True

        self.widget = CollectionsEditorWidget(self, self.data_copy,
                                              title=title, readonly=readonly,
                                              remote=remote)
        self.widget.editor.source_model.sig_setting_data.connect(
            self.save_and_close_enable)
        layout = QVBoxLayout()
        layout.addWidget(self.widget)
        self.setLayout(layout)

        # Buttons configuration
        btn_layout = QHBoxLayout()
        btn_layout.setContentsMargins(4, 4, 4, 4)
        btn_layout.addStretch()

        if not readonly:
            self.btn_save_and_close = QPushButton(_('Save and Close'))
            self.btn_save_and_close.setDisabled(True)
            self.btn_save_and_close.clicked.connect(self.accept)
            btn_layout.addWidget(self.btn_save_and_close)

        self.btn_close = QPushButton(_('Close'))
        self.btn_close.setAutoDefault(True)
        self.btn_close.setDefault(True)
        self.btn_close.clicked.connect(self.reject)
        btn_layout.addWidget(self.btn_close)

        layout.addLayout(btn_layout)

        self.setWindowTitle(self.widget.get_title())
        if icon is None:
            self.setWindowIcon(ima.icon('dictedit'))

        if sys.platform == 'darwin':
            # See spyder-ide/spyder#9051
            self.setWindowFlags(Qt.Tool)
        else:
            # Make the dialog act as a window
            self.setWindowFlags(Qt.Window)

    @Slot()
    def save_and_close_enable(self):
        """Handle the data change event to enable the save and close button."""
        if self.btn_save_and_close:
            self.btn_save_and_close.setEnabled(True)
            self.btn_save_and_close.setAutoDefault(True)
            self.btn_save_and_close.setDefault(True)

    def get_value(self):
        """Return modified copy of dictionary or list"""
        # It is import to avoid accessing Qt C++ object as it has probably
        # already been destroyed, due to the Qt.WA_DeleteOnClose attribute
        return self.data_copy


#==============================================================================
# Remote versions of CollectionsDelegate and CollectionsEditorTableView
#==============================================================================
class RemoteCollectionsDelegate(CollectionsDelegate):
    """CollectionsEditor Item Delegate"""
    def __init__(self, parent=None):
        CollectionsDelegate.__init__(self, parent)

    def get_value(self, index):
        if index.isValid():
            source_index = index.model().mapToSource(index)
            name = source_index.model().keys[source_index.row()]
            return self.parent().get_value(name)

    def set_value(self, index, value):
        if index.isValid():
            source_index = index.model().mapToSource(index)
            name = source_index.model().keys[source_index.row()]
            self.parent().new_value(name, value)


class RemoteCollectionsEditorTableView(BaseTableView):
    """DictEditor table view"""
    def __init__(self, parent, data, shellwidget=None, remote_editing=False,
                 create_menu=False):
        BaseTableView.__init__(self, parent)

        self.namespacebrowser = parent
        self.shellwidget = shellwidget
        self.var_properties = {}
        self.dictfilter = None
        self.delegate = None
        self.readonly = False

        self.source_model = CollectionsModel(
            self, data, names=True,
            minmax=self.get_conf('minmax'),
            remote=True)

        self.horizontalHeader().sectionClicked.connect(
            self.source_model.load_all)

        self.proxy_model = CollectionsCustomSortFilterProxy(self)
        self.model = self.proxy_model

        self.proxy_model.setSourceModel(self.source_model)
        self.proxy_model.setDynamicSortFilter(True)
        self.proxy_model.setFilterKeyColumn(0)  # Col 0 for Name
        self.proxy_model.setFilterCaseSensitivity(Qt.CaseInsensitive)
        self.proxy_model.setSortRole(Qt.UserRole)
        self.setModel(self.proxy_model)

        self.hideColumn(4)  # Column 4 for Score

        self.delegate = RemoteCollectionsDelegate(self)
        self.delegate.sig_free_memory_requested.connect(
            self.sig_free_memory_requested)
        self.delegate.sig_editor_creation_started.connect(
            self.sig_editor_creation_started)
        self.delegate.sig_editor_shown.connect(self.sig_editor_shown)
        self.setItemDelegate(self.delegate)

        self.setup_table()

        if create_menu:
            self.menu = self.setup_menu()

    # ------ Remote/local API -------------------------------------------------
    def get_value(self, name):
        """Get the value of a variable"""
        value = self.shellwidget.get_value(name)
        return value

    def new_value(self, name, value):
        """Create new value in data"""
        try:
            self.shellwidget.set_value(name, value)
        except TypeError as e:
            QMessageBox.critical(self, _("Error"),
                                 "TypeError: %s" % to_text_string(e))
        self.namespacebrowser.refresh_namespacebrowser()

    def remove_values(self, names):
        """Remove values from data"""
        for name in names:
            self.shellwidget.remove_value(name)
        self.namespacebrowser.refresh_namespacebrowser()

    def copy_value(self, orig_name, new_name):
        """Copy value"""
        self.shellwidget.copy_value(orig_name, new_name)
        self.namespacebrowser.refresh_namespacebrowser()

    def is_list(self, name):
        """Return True if variable is a list, a tuple or a set"""
        return self.var_properties[name]['is_list']

    def is_dict(self, name):
        """Return True if variable is a dictionary"""
        return self.var_properties[name]['is_dict']

    def get_len(self, name):
        """Return sequence length"""
        return self.var_properties[name]['len']

    def is_array(self, name):
        """Return True if variable is a NumPy array"""
        return self.var_properties[name]['is_array']

    def is_image(self, name):
        """Return True if variable is a PIL.Image image"""
        return self.var_properties[name]['is_image']

    def is_data_frame(self, name):
        """Return True if variable is a DataFrame"""
        return self.var_properties[name]['is_data_frame']

    def is_series(self, name):
        """Return True if variable is a Series"""
        return self.var_properties[name]['is_series']

    def get_array_shape(self, name):
        """Return array's shape"""
        return self.var_properties[name]['array_shape']

    def get_array_ndim(self, name):
        """Return array's ndim"""
        return self.var_properties[name]['array_ndim']

    def plot(self, name, funcname):
        """Plot item"""
        sw = self.shellwidget
        sw.execute("%%varexp --%s %s" % (funcname, name))

    def imshow(self, name):
        """Show item's image"""
        sw = self.shellwidget
        sw.execute("%%varexp --imshow %s" % name)

    def show_image(self, name):
        """Show image (item is a PIL image)"""
        command = "%s.show()" % name
        sw = self.shellwidget
        sw.execute(command)

    # ------ Other ------------------------------------------------------------
    def setup_menu(self):
        """Setup context menu."""
        menu = BaseTableView.setup_menu(self)
        return menu

    def refresh_menu(self):
        if self.var_properties:
            super().refresh_menu()

    def do_find(self, text):
        """Update the regex text for the variable finder."""
        text = text.replace(' ', '').lower()

        # Make sure everything is loaded
        self.source_model.load_all()

        self.proxy_model.set_filter(text)
        self.source_model.update_search_letters(text)

        if text:
            # TODO: Use constants for column numbers
            self.sortByColumn(4, Qt.DescendingOrder)  # Col 4 for index

    def next_row(self):
        """Move to next row from currently selected row."""
        row = self.currentIndex().row()
        rows = self.proxy_model.rowCount()
        if row + 1 == rows:
            row = -1
        self.selectRow(row + 1)

    def previous_row(self):
        """Move to previous row from currently selected row."""
        row = self.currentIndex().row()
        rows = self.proxy_model.rowCount()
        if row == 0:
            row = rows
        self.selectRow(row - 1)


class CollectionsCustomSortFilterProxy(CustomSortFilterProxy):
    """
    Custom column filter based on regex and model data.

    Reimplements 'filterAcceptsRow' to follow NamespaceBrowser model.
    Reimplements 'set_filter' to allow sorting while filtering
    """

    def get_key(self, index):
        """Return current key from source model."""
        source_index = self.mapToSource(index)
        return self.sourceModel().get_key(source_index)

    def get_index_from_key(self, key):
        """Return index using key from source model."""
        source_index = self.sourceModel().get_index_from_key(key)
        return self.mapFromSource(source_index)

    def get_value(self, index):
        """Return current value from source model."""
        source_index = self.mapToSource(index)
        return self.sourceModel().get_value(source_index)

    def set_value(self, index, value):
        """Set value in source model."""
        try:
            source_index = self.mapToSource(index)
            self.sourceModel().set_value(source_index, value)
        except AttributeError:
            # Read-only models don't have set_value method
            pass

    def set_filter(self, text):
        """Set regular expression for filter."""
        self.pattern = get_search_regex(text)
        self.invalidateFilter()

    def filterAcceptsRow(self, row_num, parent):
        """
        Qt override.

        Reimplemented from base class to allow the use of custom filtering
        using to columns (name and type).
        """
        model = self.sourceModel()
        name = to_text_string(model.row_key(row_num))
        variable_type = to_text_string(model.row_type(row_num))
        r_name = re.search(self.pattern, name)
        r_type = re.search(self.pattern, variable_type)

        if r_name is None and r_type is None:
            return False
        else:
            return True

    def lessThan(self, left, right):
        """
        Implements ordering in a natural way, as a human would sort.
        This functions enables sorting of the main variable editor table,
        which does not rely on 'self.sort()'.
        """
        leftData = self.sourceModel().data(left)
        rightData = self.sourceModel().data(right)
        try:
            if isinstance(leftData, str) and isinstance(rightData, str):
                return natsort(leftData) < natsort(rightData)
            else:
                return leftData < rightData
        except TypeError:
            # This is needed so all the elements that cannot be compared such
            # as dataframes and numpy arrays are grouped together in the
            # variable explorer. For more info see spyder-ide/spyder#14527
            return True


# =============================================================================
# Tests
# =============================================================================
def get_test_data():
    """Create test data."""
    image = PIL.Image.fromarray(np.random.randint(256, size=(100, 100)),
                                mode='P')
    testdict = {'d': 1, 'a': np.random.rand(10, 10), 'b': [1, 2]}
    testdate = datetime.date(1945, 5, 8)
    test_timedelta = datetime.timedelta(days=-1, minutes=42, seconds=13)

    try:
        import pandas as pd
    except (ModuleNotFoundError, ImportError):
        test_df = None
        test_timestamp = test_pd_td = test_dtindex = test_series = None
    else:
        test_timestamp = pd.Timestamp("1945-05-08T23:01:00.12345")
        test_pd_td = pd.Timedelta(days=2193, hours=12)
        test_dtindex = pd.date_range(start="1939-09-01T",
                                     end="1939-10-06",
                                     freq="12H")
        test_series = pd.Series({"series_name": [0, 1, 2, 3, 4, 5]})
        test_df = pd.DataFrame({"string_col": ["a", "b", "c", "d"],
                                "int_col": [0, 1, 2, 3],
                                "float_col": [1.1, 2.2, 3.3, 4.4],
                                "bool_col": [True, False, False, True]})

    class Foobar(object):

        def __init__(self):
            self.text = "toto"
            self.testdict = testdict
            self.testdate = testdate

    foobar = Foobar()
    return {'object': foobar,
            'module': np,
            'str': 'kjkj kj k j j kj k jkj',
            'unicode': to_text_string('éù', 'utf-8'),
            'list': [1, 3, [sorted, 5, 6], 'kjkj', None],
            'set': {1, 2, 1, 3, None, 'A', 'B', 'C', True, False},
            'tuple': ([1, testdate, testdict, test_timedelta], 'kjkj', None),
            'dict': testdict,
            'float': 1.2233,
            'int': 223,
            'bool': True,
            'array': np.random.rand(10, 10).astype(np.int64),
            'masked_array': np.ma.array([[1, 0], [1, 0]],
                                        mask=[[True, False], [False, False]]),
            '1D-array': np.linspace(-10, 10).astype(np.float16),
            '3D-array': np.random.randint(2, size=(5, 5, 5)).astype(np.bool_),
            'empty_array': np.array([]),
            'image': image,
            'date': testdate,
            'datetime': datetime.datetime(1945, 5, 8, 23, 1, 0, int(1.5e5)),
            'timedelta': test_timedelta,
            'complex': 2+1j,
            'complex64': np.complex64(2+1j),
            'complex128': np.complex128(9j),
            'int8_scalar': np.int8(8),
            'int16_scalar': np.int16(16),
            'int32_scalar': np.int32(32),
            'int64_scalar': np.int64(64),
            'float16_scalar': np.float16(16),
            'float32_scalar': np.float32(32),
            'float64_scalar': np.float64(64),
            'bool_scalar': np.bool(8),
            'bool__scalar': np.bool_(8),
            'timestamp': test_timestamp,
            'timedelta_pd': test_pd_td,
            'datetimeindex': test_dtindex,
            'series': test_series,
            'ddataframe': test_df,
            'None': None,
            'unsupported1': np.arccos,
            'unsupported2': np.cast,
            # Test for spyder-ide/spyder#3518.
            'big_struct_array': np.zeros(1000, dtype=[('ID', 'f8'),
                                                      ('param1', 'f8', 5000)]),
            }


def editor_test():
    """Test Collections editor."""
    dialog = CollectionsEditor()
    dialog.setup(get_test_data())
    dialog.show()


def remote_editor_test():
    """Test remote collections editor."""
    from spyder.config.manager import CONF
    from spyder_kernels.utils.nsview import (make_remote_view,
                                             REMOTE_SETTINGS)

    settings = {}
    for name in REMOTE_SETTINGS:
        settings[name] = CONF.get('variable_explorer', name)

    remote = make_remote_view(get_test_data(), settings)
    dialog = CollectionsEditor()
    dialog.setup(remote, remote=True)
    dialog.show()


if __name__ == "__main__":
    from spyder.utils.qthelpers import qapplication

    app = qapplication()  # analysis:ignore
    editor_test()
    remote_editor_test()
    app.exec_()
